Internal-combustion engine



July 14, 1925.

J. G. VlNCENT INTERNAL COMBUSTION ENGINE Filed March 26 61x01 mag Sil Patented July 14, 1925.

UNITED STATES 1,545,930 PATENT OFFICE.

JESSE G. VINCENT, OF DETROIT, MICHIGAN, SSIGNOR T0 PACKARD MOTOR CAB COI- PANY, OF DETROIT, MICHIGAN, .A CORPORATION 0F HICHIGAN.

INTERNL-COMBUSTION ENGINE.

Application filed Maren 2e, 1925. rsa1-m1 1ro. 18,341.

To all whom it may concern.'

Be it known that l, Jesse G. VINCENT, a citizen of the United States, and resident of Detroit, Wayne County, State of Michigan, have invented certain new and useful Improvements in Internal-Combustion Engines, of which the following is a specification.

This invention relates to internal combustion engines and particularly to the piston and related parts.

ln fthe manufacture of internal combustion engines, particularly those used for automobiles, motor boats, etc., the clearance between the piston and the cylinder has to be kept rather close in order to make the engine'operate quietly, and a greater degree of quietness is one of the things towards which designers of these engines are always working.

Pistons that are too tight in thecylinders are likely to stick when the engine bei comes hot and particularly if the engine is operated at high speed when it is new and before the piston and cylinder surfaces have been well worked in. Pistons that are too loose Aare noisy and usually this noise takes the form of what is technically known as piston slap. This slap is a sudden movement of the piston from one side of the cylinder to the other and usually occurs at the top of the stroke but sometimes also at the bottom of th stroke. lt is a disagreeable clicking noise and engineers have spent much money and time in trying to find a ositive cure without at the same time holdmg the factory to impracticable limits of manufacture.

It has been proposed as shown in atent to E. F. Roberts, No."1,138,892, date May 11, 1915, that piston slap may be obviated by slightly o'setting the piston pin in the iston. This produced anunbalanced efect so far as the piston head area was concerned and it seemed to in most cases entirely eliminate piston slap where the looseness of the piston was not ltoo great. It did not and was not expected to eliminate piston slap in the case of Very loose pistons.

ln the use ot odset piston pins of the character described in said Patent No. 1,138,892, it has been found that in some cases piston slap or something similar to it still existed where it was thought the odset should have cured it, and it was not until experiments with pistons more nearly balanced as to weight were used with olfset pins that important new discoveries as to the valueo the offset pin were made. Further experiment disclosed that with pistons such as shown in said Patent No. 1,138,892, while the offset pin arrangement would correct piston slap at the beginning of the firing stroke, there would in some cases remain another piston slap occurring at the beginning of the intake stroke or at the bottom of either stroke. rlhis latter slap, it was discovered, was doubtless due to the imbalance of the weight of the piston due to the odset, and, apparently it occurred when imbalance of head pressure was of less consequence. 0f course these slaps were more prevalent at the higher speeds where the inertia was considerable.

One of the objects ot the present invention, therefore, is to provide a piston and c linder construction in which the parts wilibe so related that there will be freedom. et movement between the piston and cylinder but without slapV or rattle between them.

Another object of 'the invention is to provide a piston with its pin so arranged that the iston is substantially balanced as to weig t on opposite sides of its pin bearing but is at the same time unbalanced as to head area on opposite sides ol the pin bearing.

Other objects and advantages of the invention will appear from the followin description taken 1n connection with the rawings, which forni a part of this specication, and in which:

Fig. 1 is a. vertical transverse section through an engine embodying the invention;

Fig. 2 is an enlarged perspective View of the piston shown in Fig. 1, and I Flg 3 is an enlarged' side elevation and part section through the piston.

Referring to the drawings, 1d represents the crankcase ot an interna combustion engine, 11 is the cylinder block which may comprise one or more c linders, 12 is the detachable cylinder hear?, 13 is one ot the valves, the one shown bein valve and controlling the en aast passage 14 inthe cylinder block, 15 is the valve operating mechanism, 16 is the camshaft for operating the mechanism, 17 is the iston operating in the cylinder 11, and 18 is the connecting rod which connects the piston with the crankshaft 19 mounted in bearings the exhaust 'lll lll@

in the crankcase 10. -Only the end of the crankshaft 19 is shown and on this end is mounted a flywheel 20 as by the nuts and bolts 21.

The engine here'shown is provided with means for withdrawing some of the oil from the cylinder wall and rectifying it or separating it from the more volatile constituents with which it may have become contaminated. This means consists of an up r compartment 30 which is heated by a jac et 31A connected by a passa e 32 with the exhaust manifold 33 of t e engine, and a lower compartment 34 which is preferably air cooled as by fins 35 and is connected by an outlet pipe 36 leading to the crankcase 10. A pipe 37 leads from a port 38 in the side of the cylinder 11 to the compartment 30 and a pipe 39 leads from a stand pipe 40 in the upper compartment 30 to a port 41 in the intake manifold 42. There is a float 43 in the lower compartment or chamber 34, which float operates a trip mechanism 44 connected to alternately open and close valves 45 and 46 which control ports 47 and 48'respectively, the port 47 extending from the upper compartment 30 to the lower compartment 34 and the port 48 being a relief port. There is also a ball valve 49 at the outlet from the lower compartment 34. Telescoping bales 50 and 51 are provided in the upper compartment 30.

.The operation of this mechanism is as follows: Immediately as the engine is started suction is produced in the intake manifold 42 which causes a partial vacuum in both the upper and lower compartments 30 and 34. This causes the ball valve 49 to move up against .its seat in the bottom of the lower compartment so that a partial vacuum is maintained in both compartments. It is assumed that the float 43 is in the low position in which it is shown in Fig. 1 and in this position the relief valve 46 is closed and the valve 45 is open. In Th some cases there are two erts 47 and similar valves for them so t at oil may pass through one port and air may pass out through the other. However, one port is suilicient if it is made large enough. The oil and unburned fuel is thus drawn through the port 38 and pipe 37,l into the space between baille 50 and the wall of the compart- .inent 30. As the oil fills the compartment the heat generated by the exhaust of the engine heats the oil and the volatile constituents thereof are driven olf. These, in gaseous form, are drawn through the stand pi 39 and the pipe' 41 into the intake manifo d 42. The oil gradually flows over the top of the baille 50 and after thus being separated from its more volatile constituents is precipitated to the bottom of that baille and asses through the connecting port 47 to the ower compartment 34, causmg the float to be raised gradually in. that compartment. y When the float has reached a certain height it causes the trip mechanism 44 to close the valve or valves 45 and open the relief valve This of course causes the oat 43 to drop and again the trip mechanism 44 is operated and the valves 45 and 46 assume their former position. This completes the cycle and the same thing is gone through with again.

The port 38 in the cylinder 11 is arranged so that it is traversed by the piston ,throughout its stroke. When the piston is at its lowest point the port 38 is preferably opposite one of the piston ring grooves. This ring groove is indicated at 60. The piston is also preferably formed with a; longitudinal groove 61 which communicates with the groove and the port 38 so that the suction at the port 38 will draw oil from the piston ring groove through about onehalf of each stroke of the piston. During the remainder of the stroke of the piston, or when the main part of the piston is above the port 38, the port 38 is covered and thereby closed by an extension 62 extending downwardly from one side of the skirt 63 of the piston. The head of the piston is indicated at 64 and is referably formed normal to the sides ofp the piston. Interiorly the piston is formed with bosses 65 in which are bearings 66 for a piston pin 67 mounted on the up r end of the connecting rod 18 above re erred to. With this construction of piston it is evident that that part which is on the side of the piston on which the extension 62 is formed is of greater weight than is that part of the piston on the other side of a median plane through the longitudinal axis of the piston. emedian plane referred to is indicated by the broken line 70 in Fig. 1 and another broken line 71 indicates the parallel and olfset plane in which the axis of the piston pin 67 1s arranged. The pin bearing 66 for the piston pin 67 is olset on that side of the piston to which the extension 62 is connected, or in other words, the offset is towards the heavier side of the piston. The offset is just sullicient and the additional weight of the extension 63 is such that the piston is substantiall balanced as to weight on opposite sides o a plane such as the plane 1 passingthrough the center of the piston pin bearing. Thus the rapidl reciprocation of the piston in the cylinder will not find an unbalanced condition of weight on the piston pin. At the same-time, the offset arrangement of the iston pin will produce an unbalanced con ition as to the ead area and at the beginning of the firing stroke this unbalanced condition will tend to eliminate the piston slap that might` exist in the'ease of a centrally located pin.

While lhave herein described in some detail a speciiwembodinient of mdy invention, which I deem to be new an advantageous and may specifically claim, l do not `desire it to be undersood that my invention is limited to the exact details of the construction, as it Will be apparent that changes may be made therein without dev parting from the spirit or scope of niy invention.

' Having thus described my invention, what I claim and desire to secure by Letters Patent is:

l. A piston vcomprising a head, a skirt, and a pin bearing, said parts being so formed and relatively arranged that the pison is substantially balanced as to Weight, and is unbalanced as to head area, on opposite sides oi" its pin bearing.

2. A piston compi'ising a head, a skii's, and a boss having a pin bearing therein, said piston being substantially balanced as to Welgh on opposite sides of said pin bearing and unbalanced as to head area on opposite sides of said pin bearing.

3. A biston comprising a head, a skirt and a pin boss` said piston heaviei1 on one side of a longif ".1- plane parallel to said boss the; n the other side, and the pin bearing in said boss offset from said plane to substantially balance the Weight oi the piston on said bearing.

4f. A piston having its head end formed 'substantially normal to its sides, having greater weight in its skir"l on one side of a longitudinal median plane than on the other?, and having its pin bearing parallel to and oi'set from said median plane.

5. In an internal combusion engine, the combination with the cylinder, of a pislon therein having its skirt oined heavier on one side of a longitudinal median plane alien on the other, and a connecting rod pivor'ned to said piston, said pivo being onl slightly oiset at one side of said median plane.

6. ln an internal combustion engine, combination of a cylinder having a side perl; therein, a piston having a skirt oiiaed with a groove to regisl'ei with said pont dining part of the travel of the piston and sai skirt having an extension at one side only for coveiing said poni; when ihe veel: ci the pis'fon has passed above the poet, said entension making the piston slighily heaviei1 on than side, and a connecting rod. pivote-ol io said piston enan axis only slighly effi.

set from the pision axis and lon/'ands iiaz side of Jdie piston having said enzension.

ln testimony whereof l an my signanie,

i JESSE G. lTllNCEIHT. 

